///////////////////////////////////////////////////////////////////////////////////
/// OpenGL Mathematics (glm.g-truc.net)
///
/// Copyright (c) 2005 - 2015 G-Truc Creation (www.g-truc.net)
/// Permission is hereby granted, free of charge, to any person obtaining a copy
/// of this software and associated documentation files (the "Software"), to deal
/// in the Software without restriction, including without limitation the rights
/// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
/// copies of the Software, and to permit persons to whom the Software is
/// furnished to do so, subject to the following conditions:
/// 
/// The above copyright notice and this permission notice shall be included in
/// all copies or substantial portions of the Software.
/// 
/// Restrictions:
///		By making use of the Software for military purposes, you choose to make
///		a Bunny unhappy.
/// 
/// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
/// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
/// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
/// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
/// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
/// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
/// THE SOFTWARE.
///
/// @ref gtx_vector_angle
/// @file glm/gtx/vector_angle.inl
/// @date 2005-12-30 / 2011-06-07
/// @author Christophe Riccio
///////////////////////////////////////////////////////////////////////////////////

namespace glm {
    template<typename genType>
    GLM_FUNC_QUALIFIER genType
    angle
    (
            genType
    const & x,
    genType const &y
    ) {
    GLM_STATIC_ASSERT(std::numeric_limits<genType>::is_iec559,
    "'angle' only accept floating-point inputs");
    return
    acos(clamp(dot(x, y), genType(-1), genType(1))
    );
}

template<typename T, precision P, template<typename, precision> class vecType>
GLM_FUNC_QUALIFIER T
angle
(
        vecType<T, P>
const & x,
vecType<T, P> const &y
)
{
GLM_STATIC_ASSERT(std::numeric_limits<T>::is_iec559,
"'angle' only accept floating-point inputs");
return
acos(clamp(dot(x, y), T(-1), T(1))
);
}

//! \todo epsilon is hard coded to 0.01
template<typename T, precision P>
GLM_FUNC_QUALIFIER T
orientedAngle
(
        tvec2<T, P>
const & x,
tvec2 <T, P> const &y
)
{
GLM_STATIC_ASSERT(std::numeric_limits<T>::is_iec559,
"'orientedAngle' only accept floating-point inputs");

T const Angle(acos(clamp(dot(x, y), T(-1), T(1)

)));

if(
all(epsilonEqual(y, glm::rotate(x, Angle), T(0.0001))
))
return
Angle;
else
return -
Angle;
}

template<typename T, precision P>
GLM_FUNC_QUALIFIER T
orientedAngle
(
        tvec3<T, P>
const & x,
tvec3 <T, P> const &y,
        tvec3<T, P>
const & ref
)
{
GLM_STATIC_ASSERT(std::numeric_limits<T>::is_iec559,
"'orientedAngle' only accept floating-point inputs");

T const Angle(acos(clamp(dot(x, y), T(-1), T(1)

)));
return
mix(Angle,
-Angle,
dot(ref, cross(x, y)
) < T(0));
}
}//namespace glm
